Optical glasses



Patented June 27, 1950 UNITED STATES ATENT OFFICE OPTICAL GLASSES Raymond Edward Bastick and Ta-Hang Wang, Smethwick, England, assignors to Chance Brothers Limited, Smethwick, England No Drawing. Application March 28, 1946, Serial In Great Britain August 4, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires August 4, 1964 1 Claim.

This invention relates to optical glasses, and particularly glasses required for photographic lenses.

The invention comprises glasses having the following essential constituents, namely:

Percent Silica (SiOz) 21.5 Boron oxide (B203) 19.0 Barium oxide (BaO) 45.0 Thorium oxide (ThO2) 14.5 Refractive index m 1.650 Abbe constant 0 58.5

2 B203, 45% BaO, and 14.5% ThOz the values of m and 12 being 1.650 and 58.5 respectively.

RAYMOND EDWARD BASTICK. TA-HANC-r WANG.

REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS Number Name Date 1,943,051 Berger Jan. 9, 1934 15 2,406,580 Bastick et a1. Aug. 27, 1946 FOREIGN PATENTS Number Country Date 596,513 Germany 1934 

